More Bush Environmentalism

[illustri]

well the genes expressed by the wild parents may have been selected AGAINST, or merely die out in the fisheries: for example, say wild rivers have a certain amount of lead in them, and wild salmon who have genes that allow lead to be excreted or metabolized safely before poisoning survive OK?

now, for sample of those wild fish in the fisheries, there no lead in their treated water, there is no pressure for that lead-resistent gene to be selected during mating, perhaps it is even breed out or made junk in their genome since its unnecessary --- this happens over the course of several generations or breedings in the fisheries

end result, release those fish into the wild and they may survive to breed, but there is a huge environmental disadvantage on them because unlike their original wild parents, they no longer have the lead-resistant gene, eventually they and their offspring die out

to answer your question also, i doubt they actively SELECT traits for fish in the tank, it is more the RESULT rather than the cause of the concerns, if i were an enterprising fishery manager, i would just like i said, get a whole BUNCH of wild fish, let them breed for several generations in my tanks, that is enough to "choose" the best fish FOR MY FISHERY because those that survive to breed are best fitted for MY TANKS (ie. i dont care whether they are fitted for the wild or not)

 

[charrison]

Originally posted by: illustri
well the genes expressed by the wild parents may have been selected AGAINST, or merely die out in the fisheries: for example, say wild rivers have a certain amount of lead in them, and wild salmon who have genes that allow lead to be excreted or metabolized safely before poisoning survive OK?

now, for sample of those wild fish in the fisheries, there no lead in their treated water, there is no pressure for that lead-resistent gene to be selected during mating, perhaps it is even breed out or made junk in their genome since its unnecessary --- this happens over the course of several generations or breedings in the fisheries

end result, release those fish into the wild and they may survive to breed, but there is a huge environmental disadvantage on them because unlike their original wild parents, they no longer have the lead-resistant gene, eventually they and their offspring die out

to answer your question also, i doubt they actively SELECT traits for fish in the tank, it is more the RESULT rather than the cause of the concerns, if i were an enterprising fishery manager, i would just like i said, get a whole BUNCH of wild fish, let them breed for several generations in my tanks, that is enough to "choose" the best fish FOR MY FISHERY because those that survive to breed are best fitted for MY TANKS (ie. i dont care whether they are fitted for the wild or not)

The example you provide is not really a good one, as once the fish go back into the wild, they will be once again exposed to that lead. THe fish dont stay at the hatchery very long.


But are you prepared to give up your samon and make the enviromentalist happy?

 

[illustri]

you know i actually dont care all that much about the salmon population as long as i can have my fill of good eatin' in my lifetime, i guess my kid'll just have to find another animal as tasty to eat

but i was trying to explain one facet of the environmentalist arguments -- which is simply this: if you kill the salmon in the wild you'll decrease the variability that we all know is essential for survival, replacing them with farm bred salmon doesn't help because the cultivated fish are really NOT genetically diverse as in the wild: and just like you say the same pressures are on them now in the wild when they are released, but they may NOT survive to breeding ages due to lack of something that wild salmon has -- end result you have lots of fish in the fisheries, and none in the wild - a big chunk of the ecosystem taken out

 

[illustri]

you know i read my own posts, and think: maybe I'm not being clear on my explanation

so here:

wild salmon are dying
get a bunch of wild salmon and breed them in fisheries
fishery salmon are dying - they are in new environment they haven't yet adapted to
take the surviving fishery salmon and breed them
replace wild salmon (still dying) with successful fishery salmon
fishery salmon die in the wild

there are no more wild salmon to breed
you can only continue breeding fishery salmon that die in the wild
less salmon in the wild
more in the fishery

a big slippery slope arguement, but I believe some points are valid